The present invention relates to endoscopic surgical devices, and in particular to valve assemblies used to control the flow of irrigation fluid in such devices.
Endoscopic devices are customarily provided with an irrigation port that conducts an irrigation liquid to the viewing area at the end of the endoscopic device. One prior-art approach is to pressurize irrigation fluid in an IV fluid bag, and then to supply the pressurized irrigation fluid directly into an endoscope such as an ureteroscope. The endoscope includes integral valves that are generally operated with one hand while the other hand holds the handpiece of the endoscope. The advantage of this system is that the irrigation fluid is pressurized, thereby providing dilation of a ureter and good visibility. One potential disadvantage with this type of irrigating system is that it may be difficult to control fluid flow since two hands are required. If the fluid flow is not controlled properly, a stone can be dislodged back into the middle or upper ureter by an excessively high rate of flow. Also, in the event of extravasation, uncontrolled amounts of fluid can flow into the retroperitoneum.
Another type of irrigation system is a hand-operated, pressurized irrigating system commercially manufactured by Bard, Boston Scientific, and ACMI. This approach allows the amount of fluid being injected to be controlled, but the apparatus is relatively bulky. This system is mounted separately from the ureteroscope, and separate hands are used to hold the handpiece of the ureteroscope and to control the flow of irrigation fluid. On occasion, an assistant controls fluid flow while the physician holds the endoscope in the left hand and performs an endoscopic procedure with the right hand. In this case, precise control of the rate of fluid flow is difficult, because oral instructions are slower and less precise than direct manual control by the physician.
A third type of irrigation system includes two or more syringes that are operated by an assistant one at a time to supply pressurized irrigation fluid to the endoscopic device. Generally a valve is provided that allows the assistant to fill one of the syringes while the other is in use.
A fourth type of irrigation system includes a roller pump mechanism that delivers irrigation fluid at a constant set pressure. This system may incorporate a blow-off valve to prevent excessive pressure, and it is generally used in endoscopic specialties such as orthopedics in performing arthroscopies. This system requires the use of an electric motor and controller, and it is therefore costly and bulky.
Goodman U.S. Pat. No. 4,567,880 discloses an endoscopic device having a three-way valve forming a permanent portion of the handpiece of the endoscope. This system allows a physician to control the flow of irrigation fluid with the same hand as that used to hold the handpiece. However, the Goodman system requires a specially constructed endoscope, and the irrigation system is an integral part of the endoscope. This limits the irrigation system to use with one particular endoscope.
The present invention is directed to an improved system and method for controlling the flow of irrigation fluid in an endoscopic device.
The preferred embodiment described below includes a modular valve assembly having a housing that carries an inlet port, an outlet port and a valve. The valve can be manually controlled by a user with the hand holding the endoscope to selectively allow or block fluid flow from the inlet port to the outlet port.
In use, the housing is releasably mounted to the handpiece of an endoscope by a pressure-sensitive adhesive, strap, or other fastener. The inlet port is connected to a source of pressurized irrigation fluid and the outlet port is connected to the irrigation port of the endoscope. The physician can then use a single hand to perform both the function of holding the handpiece and the function of controlling the flow of irrigation fluid. This leaves the other hand free for performing a surgical procedure via the working port of the endoscope, e.g., positioning and manipulating a stone extraction basket. Once the surgical procedure is completed, the modular housing can simply be removed from the endoscope and discarded. This eliminates the need to clean the valve or the ports of the valve assembly.
This section has been provided by way of general introduction, and it should not be used to narrow the scope of the following claims.